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Drop Free Lapping -- non-size changing

Drop Free Lapping -- non-size changing is done using comet powder. I still clean off the gas check shank on the lap bullet with a file (taking it way undersized) so it doesn't change anything in the mold around the gas check shank area.

Goal here is to get the bullets to drop free and to see if there are any restricted areas or if perhaps the cavities are different sizes. This form of lapping is very mild and will not change any sizes appreciably (not unless you do it like forever).

Being the world famed Wobbly Goblin Mold those two cavities are currently two different sizes -- I have PM'd Ric to ask him what size he wants both the cavities to be as our next step is doing the size change lapping.

Last edited by Oldfeller; 11-06-2005 at 04:59 AM.

"Had guns, must travel" reads the card of a man ...
Existing daily from his suitcase in a "temporary" land
Does his posting from a lobby -- he's now a modern Paladin
Paladin, Paladin, where do you roam? (far, far from home ....)

Kelly- I see where you're going with this. Kudos on a fine article. I really need to take care of my Lee's. A lot of what you're saying carries over into pretty much every other makers moulds, with the possible exception of SOME of Walt Melanders NEI moulds that are just perfect. Even with those the handle issue comes up. Again, great job!

T'aint no impress to it, here's the tool ready to do the deed to the front half of the bullet (down where the two lateral pins are). You crush this first, lap it back to round then crush the top half using a good bit less force (if needed).

I keep telling you LEE molds aren't durable and they close themselves down slowly due to simple knurling wear and sine form wear -- don't you think I can do it on purpose whenever I want to?

I just crush it some in my widdle bitty precision machinist vise.

Hell, LEE uses the same trick on round ball molds (because they can't cut a round cavity) -- they throw in a carbide ball bearing and crush the mold around it EXACTLY like I am doing here.

If I had me a hardened steel lathed bullet, I bet I could really fix this wobbly goblin sack of **** back up.

(note that thought -- use harded steel "master bullet" as a means of making precise mold corrections very quickly and cheaply rather than sweating out all the finest machining and lapping methods. It would also take out the cavity to cavity variation that exists in a six banger mold. If I ever get LEE'd again on a group mold buy and have to fix it -- this thought might get considered even more strongly.)

Now, from the litter of slugs in the picture you probably figured that the mold is dropping free pretty good now. Size is still slightly off one cavity to the other, but the total casting span now runs at .3600"-.3615" all roundness and cavity to cavity variation included.

The two leaning up against the vise had a minor very thin nose flash (which would go away if I crushed the nose end of the mold in the vise) which is fixable two ways. The flash comes from damage done digging at the lead stuck down at the pins, it is the remainder or shadow from fixing the deep scratch from the pocket knife.

Remember I told you if the handle fixing loctite got loose in the mold you would have to chip it out? And that it followed the "perfect form" of the mold and technically wasn't a "bad thing"?

Yup, we can do it on pupose too if we want to -- a little dab will do you.
(oil the other side of the mold so you don't have to beat the silly mold open, you just got it working good and you don't need to be hammering on it at this stage of things).

So, both cavities (roundness included) meet LEE's factory spec which is .003" for size and .001" for roundness. They cast .3600"-.3615" measuring over all the bands and they only flash that tiny flash when power poured (I got over 100 sitting here with no flash at all).

So, I ain't turning that allen wrench handle nor getting out the loctite bottle until Waksupi gets back to me to say what he wants.

(this figure is roughly 2 times better compared to the 0.84% original figure. It includes the tiny flash at the gas check/sprue plate, but that should count as it rides out the muzzle under the gas check as part of the bullet weight variation)

Me, I'd toss out the 1-50 nose flashers at lubricising whenever they showed up as a good sorting criteria and I'd call this puppy fixed. If it irritated me again later, I'd fix it again.

And a LEE mold WILL come back to irritate you later, and you will have to fix it and fix it and fix it and fix it ..... until you finally give up and give it the Jumptrap 12 pound fix.

Remember, I told you I put in a central vent (between the cavities) which is not flashing at all. The goblin will eventually lose this vent as the mold halves settle into each other, but by then Ric will have him a whole NEW crop of issues from his NOT DURABLE (bound to fail again) cheap piece of **** LEE two cavity mold.

Oh Ric, what do want me to do ........

(answer = ship it back, it's done)

The final "drop-free" release lap slug is in the inner cavity, the screw for the lap slug is taped to the handle and I baby powdered the thing good with moly powder before wrapping it up for the trip back home. (note the use of the rubber band on the handles to keep shippng fretting damage away -- LEE Sr. used to do this but a rubber band cost too much money now so they let your new mold get all beat up before you ever get to see it -- Thank YOU, LEE Jr.)

All you need to do is open it up, blow it out, warm it up real good (full casting temperature) and go to casting frosty bullets from the very first cast. Then don't do anything to it and let's see how long the Wobbly Goblin goes before deciding on some new way to screw up for you.

(it's a LEE -- we can have confidence it will find a way).

Note: the first couple of casts will have some moly powder embedded into the lead slug, so just put the first 3-4 casts back into the pot.

Last edited by Oldfeller; 11-06-2005 at 06:17 PM.

"Had guns, must travel" reads the card of a man ...
Existing daily from his suitcase in a "temporary" land
Does his posting from a lobby -- he's now a modern Paladin
Paladin, Paladin, where do you roam? (far, far from home ....)

I think one of the problems with the cheapo Lee moulds is they must use the cheapest, softest, lowest grade of aluminum known to man. Hell you can carve it with a pocket knife. If they'd use a better grade the moulds might survive a while longer.

One major problem I have had with Lee moulds is the **** bottom horizonal alignment pin falling out. I'll be casting and start getting messed up bullets and go huh, what...then see the pin is gone. Lucky I find it in my bullet pile. Pain in the *** to put back in and work on because the mould and pin both are hot.

I always thought of Lee products as CHEAP. Some of them are okay, the rest are like we said when I was a kid "Japanese junk". I guess today you could almost say "Chinese junk" but they are catching up on technology at an alarming rate.

Final thoughts

Some final thoughts as I tape the box back up.

It was a good "fix it" sticky and we did get that new mold "click" back for the Goblin (when the alignment features snap crisply into indexed location). But the mold grew a thou in the process as it had to grow some to get the roundess and cavity to cavity consistency back.

Size is more consistent now and weight is a whole lot more consistent. It is dropping free now, but that is the first thing that you lose on a LEE mold. (that's why I'm shipping the lap with the mold)

I never did ask if Ric casts with a bottom pour pot or a ladle ....

Ladle guys carry their flux with them into the cavities with the poured lead -- them ladle guys "crust up" their molds pretty much consistently too.

Anyhow, I am pretty good at doing something nobody should have to do -- chase the ever-changing condition of LEE molds due to bad materials and a shoddy design that is quickly vunerable to very simple wear.

I'm not buying any more LEE molds (except maybe the custom six bangers).

====================================

******** like this LEE fix-it stuff is no way to spend the limited hours of life you got left (no matter how young or old you are).

====================================

sticky done -- Oldfeller

Last edited by Oldfeller; 11-06-2005 at 01:38 PM.

"Had guns, must travel" reads the card of a man ...
Existing daily from his suitcase in a "temporary" land
Does his posting from a lobby -- he's now a modern Paladin
Paladin, Paladin, where do you roam? (far, far from home ....)

"Had guns, must travel" reads the card of a man ...
Existing daily from his suitcase in a "temporary" land
Does his posting from a lobby -- he's now a modern Paladin
Paladin, Paladin, where do you roam? (far, far from home ....)

Kelly, it got back here. The donkey they haul the mail on here, must be lame. I don't know if I will be able to play in the marichi band anymore, since you have sucessfully removed all the shakes, rattles, and collywobbles. Thanks for a good job, and for showing everone the technique!

Boy, I didn't have an idea how uninformed I was until I read all this. You guys know more about moulds than I'll ever get figured out. I used a Lee mould a long time ago and finally got so fed up that I trashed it and swore I'd never use a cast bullet again. Well, it took me about 30 yrs. but here I am again, trying to do it. This time I'm trying Saeco moulds. My first one was defective. I sent it back. They couldn't fix it so made me another. It wasn't perfect, either. But it worked. So they sent off to have a new cherry made whilst I suffered along with the replacement mould. Now, nearly a year later, they have a mould cut with a new cherry that they say is perfect. They are sending it to me to see if it works. I sure hope it's right this time. I don't know enough to fix my own nor do I have the inclination to go buy a machine shop so I can fix a mould. You can bet if I encounter any problems I'll consult you fellas!

Oldfeller is a genius!
Yes, Lee uses the softest **** aluminum because it is CHEAP! I use aircraft aluminum for my moulds. I use stainless for the sprue cutters. I never get gouges on the mould tops. Leaving the marks from an end mill on the bottom of the sprue plate and the top of the mould does wonders too. Rapine mould prep does a great job too.
I don't know if you guys have read my posts on freezing the blocks and re-cutting the cavities with a warm cherry. Some of my moulds come out undersize from block to block but the right size at the parting line. Freezing and re-cutting makes them round and the right size.
I wonder if this would work when lapping a cavity? Get some boolits imbedded and ready, freeze the blocks for an hour or more, then lap. Re-freeze between laps. This might get the lap to cut where you want it to instead of at the parting line. I haven't tried it yet, but will in the future. If any of you do, please post it.
I cast new laps after lapping to keep the boolit size up. Be a pain to cool the mould and re-freeze before using a new lap. but the time should be worth it.

From what I understand talking to Buckshot is it doesn't matter if the aluminum is harder by tempering or not. Buckshot said that the heat of casting with an aluminum mould will take any temper out of them. I believe he is right. If he is then you're wasting your money on a more expensive aluminum. The one thing that Buckshot and I agree on about a harder aluminum mould are those that have been anodized. In fact my original Thompson Center 50 cal Maxi-Ball mould, made by Lyman for them, is anodized and it's held up really good for 35 yrs or more. Just my two pence.

Joe, I don't buy anything! This is scrap aluminum from when I worked for United Air Lines. It does not get soft after casting. The moulds do not get hot enough to change. A friend gave me a length of 6061 aluminum to play with and it made great moulds with no galling of the top surface. The only way I will get a scratch is if I miss a burr on the sprue plate. I have no scratches on my moulds, I have them on Lyman iron moulds.
The only money I spend is on some drill rod for cherries, about $5 for 3 feet and Rapine handles which are only $14. I have three sets and I just change handles from mould to mould.
There is a great difference between my metal and the Lee metal.
You have to remember that aluminum is alloyed for different purposes and heat does not change the alloy. If this was true, the addition of tin and antimony to lead would be useless. Tool steel would be junk if heat changed it by making it soft by ruining the alloy. It can be re-hardened, the alloy is still there unless you burn it off with extreme heat.

Ack !! Thread hijacking in progress ....

Ack !! Thread hijacking in progress .... Hijacking a Sticky no less !!

Now I promised everyone I would post the statistical analysis of an entire LEE production run -- this one was the 7mm Soup Can run which was 50 molds long but I only got hands on to the first 25 molds for measurement purposes.

First, let me explain why a caliper was used instead of a micrometer -- the mike I had available had a clicker thimble on it and it would absolutely reliably crush all parting line irregularities flat as a pancake instead of measuring them and it put little bitty minute flat spots on thin ogive "max diameter" areas too (once you laboriously located them and tried to measure them). In other words the mike really wasn't working for me at all and the caliper did just dandy in both finding and measuring the "soft" parting line areas and them frail and downright tiny ogive maximum diameter points.

A caliper isn't an ideal statistical tool. First, it lacks fine division or discernation-- it will only discern to 5 tenth increments while a mike will discern to single tenths (and some good ones will do 50 millionths which is half again finer discernation). Second, a caliper can be "driven" by an operator to achieve a desired goal (conciously or unconciously) and a mike generally tends to be more impartial as well as being more accurate -- on solid steel parts anyway.

But, hey - when you are dealing with lead bullets the only reliable mike I have ever found that won't crush things is a Mitutoyo QuickMike with the "hands off" fast action low contact force slip-type thimble. But the silly things cost $450 and I don't own one personally. And my current company doesn't own one either.

So I used a Mitutoyo caliper for this study -- shame on me. At least I didn't "drive" it, I always recorded what I got and I took all measurements twice and I used two different bullets per mold to make sure I had some basis to call out an "off" number with some level of confidence.

=============================

What can cause cast bullets to vary?

Many things, alloy - temperature - casting speed - head (pour distance) - open close variation on the alignment pins - closure force on the mold cavities - lordy, there are a lot of things. I tried to take some out just to keep things simple and keep things as neat as possible.

To attempt to be fair, all casting was done exactly as the molds were shipped using a Lee handle set to provide the clamping force and using a Lee 10 pound bottom pour pot allowing the nipple to rest in the sprue cone and using the nozzle as a forced pour arrangement. In short, I wanted as wrinkle free a first cast bullet as I could get and I wanted to reflect the size of the cut cavities in WW metal without any smoke or spray or other sorts of stuff that folks normally use on molds.

(smoke and spray all make mold cavities cast smaller, you know that, right?)

So, here is the raw data in picture format so you can see the organization of the rows and columns.

Once again, right click on the pics, hit copy then paste it into your favorite graphics program so you can expand it enough to acutally see the numbers.

Got to split this post in two -- list can't take the whole enchalada. This seems as good a spot as any ...

Last edited by Oldfeller; 04-12-2006 at 05:58 PM.

"Had guns, must travel" reads the card of a man ...
Existing daily from his suitcase in a "temporary" land
Does his posting from a lobby -- he's now a modern Paladin
Paladin, Paladin, where do you roam? (far, far from home ....)

continued

The center two cavities were cast and both separate bullets were measured at the nose ogive max diameter section (a wee tiny little zone really) and over the length of the driver bands. A measurement was recorded over the parting line and at 90 degrees out from the parting line -- this reflects roundness of the bullet with most slugs being smaller at the parting line (which means the clamping force used during machining was greater than the clamping force available off the LEE handle set -- the cavity holes were round when they were cut but they were just clamped a lot harder at that point in time)

Cutting to the chase, LEE made some out of print cavity holes during this mold run dispite being given a full .003" tolerance as per their spec sheet requirements. Most of this error was locational -- where they parked or set up the process.

If you want to be able to really read these graphs, right click on them, copy them then paste them into your favorite graphics program and expand the image back to a "readable" size.

Notice the bands were set up at the low end of spec and the nose was set up at the upper end of spec. I drummed at Doug DO NOT, REPEAT DO NOT GO UNDERSIZE on the nose so I can see where he maxed out on the nose. Why he went short on the driver bands, I dunno. At least he was actually touching a print limit instead of being .002" undersized as has sometimes happened recently, so it is not to complain I guess.

==========================================

Now. lets talk about CAPABILITY to a .003" tolerance for this run. Obviously when you have one item hanging half out the top and the other item hanging half out the bottom of your .003" tolerance range and you are measuring out of print non-conformance in whole percents (and your PPK is a negative number because the center of a distribution is completely out of tolerance) -- you are not capable of holding the .003" tolerance.

Now, let's talk some fairy juice. IF Doug could center his process in the middle of spec his sigma numbers and histogram spread indicate he COULD maybe get them all into a .003" tolerance. His PPK, Cpk, Z-score or whatever flavor of capability index that you like to use wouldn't be very good, but IF Doug could center his process in the middle of a spec he COULD get them all in print with a .003" tolerance. Theoretically.

He sure as **** has no chance at all with a +/-.001" tolerance, much less when given a total tolerance of .001" (+/-0.0005") So, give him a teeny tiny tolerance span if you want to -- but don't be too surprised when he misses it by a couple of thousandths. Design your bullets to work with a .003" tolerance span and Doug has a fighting chance to make you a run of molds.

Now, is the process under statistical control? Yes. it just isn't as good as you would like it to be.

Note the range charts (bottom portions) please. The sample size is the same as the number of times a bullet got measured (parting line to 90 degrees out) so the calculated range chart is really the statistical expression of bullet roundness. LEE might cut cavities perfectly round, but the blocks move on the alignment pins some and there is open-close variation and clamping force variation that gives you out of round bullets to the tune of a thou and a half (right regularly too).

I may have some more to add to this as I play with the data, but you begin to see why LEE asks us to put .003" tolerance ranges on things -- they need it.

Adder thought -- if your range chart upper limit is statistically generated at .0016" (roundness variation within a bullet) how could you even begin to think you could give somebody a .001" total tolerance spread -- LEE USES UP more than that in roundness alone -- much less covering the larger pure dimetrical size variation that is going on at the same time.

Amusing thought -- the 3 oversized molds that were supposed to be enlarged to a thou over print specification on the driver bands never even got close to that neighborhood -- actually they fall right into both sets of control charts and both sets of histograms. Statistically, they were not really statistically "different" from the normal run molds.

Oldfeller

Last edited by Oldfeller; 04-12-2006 at 03:08 AM.

"Had guns, must travel" reads the card of a man ...
Existing daily from his suitcase in a "temporary" land
Does his posting from a lobby -- he's now a modern Paladin
Paladin, Paladin, where do you roam? (far, far from home ....)

"Had guns, must travel" reads the card of a man ...
Existing daily from his suitcase in a "temporary" land
Does his posting from a lobby -- he's now a modern Paladin
Paladin, Paladin, where do you roam? (far, far from home ....)

A Democrat that owns Guns is like a Vegan that owns Cats...
C2N14... because life is not energetic enough.Gott und Gewehr mit uns!...
Death is only The End if you assume the Story is about You.
1.618034 Fnordמנא, מנא, תקל, ופרסין - Daniel 5:25-28 - Got 7.62?

I would think lapping would tend to give you ovality issues on your round style bullet. The lapping action would be most effective at the "equator" of the spun bullet but it would be relatively ineffective up at the north and south poles of the spun bullet. Why is this? The embedded grit would be moving very little (and relatively slowly) as it made that tiny orbit up at the N & S poles.

When you lap a normal bullet check the amount of removal that takes place on the center of the meplat of the bullet -- very very little if any gets removed.

Oldfeller

"Had guns, must travel" reads the card of a man ...
Existing daily from his suitcase in a "temporary" land
Does his posting from a lobby -- he's now a modern Paladin
Paladin, Paladin, where do you roam? (far, far from home ....)